A PORTRAIT OF THE TAMPA BAY ESTUARY

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WHITE IBIS MOBILE

With its distinctive down-curved, orange-red bill and habit of traveling in a flock, the white ibis is among the most recognizable of Tampa Bay's spectacular wading birds. Its appetite for mole crickets and other lawn pests has earned it the nickname "Gardener's Friend."

But despite its familiarity, the white ibis is a species in trouble.

Although the ibis is still one of the most common wading birds in Florida, scientists estimate its population may have declined by as much as 70% in the last 35 years, prompting the Florida Fish and Wildlife Conservation Commission to designate it a "Species of Special Concern." Much of this decline is likely the result of habitat loss associated with development.

In the Tampa Bay area, white ibis have a critical stronghold, with four large breeding colonies in the bay itself, one in Clearwater Harbor and a smaller inland site. Ibis that nest at one of these sites may travel as far as 15-20 miles inland to find crayfish, small fish and frogs, plus mole crickets, grubs, chinch bugs and other crop and garden pests to feed their young. Access to freshwater food sources is crucial, because ibis chicks cannot tolerate the salty fiddler crabs and other coastal crustaceans their parents eat. In fact, studies show that juvenile ibis fed only saltwater animals perish.

Therefore, protection of inland freshwater wetlands is crucial to the survival of white ibis. Even small "frog ponds" - temporary ponds that hold water only during the rainy season - can provide a valuable "grocery store" for ibis parents struggling to find food for their hungry nestlings.

The number of white ibis nesting in Tampa Bay fluctuates from about 6,000 to 11,000 annually. In 1998 there was an extraordinary increase in nests, up to 17,000, when El Nino recharged wetlands just prior to a strong drawdown that began just as eggs hatched. Since then, nesting has returned to more typical levels.

Although white ibis has declined locally by about two-thirds since the 1940s, the Tampa Bay population remains one of the largest in Florida. Adult white ibis are pure white with black wing tips. Their bare face and bill are orange in color most of the year, but turn a brilliant scarlet during breeding season. Immature, or juvenile, ibis are brown with white bellies for the first couple of years of their life, turning white as they mature.